The cards they are showing are good quality, but I still want to see more boxing considering the stupid prices they charge.

You aren't paying for boxing, the high price is for football solely, everything else is just sky throwing in extras including F1.
You get enough boxing fans watching to make them as attractive to advertisers and a credible revenue stream (a la football)then SKY will bid and get every card available.

This is never going to happen, not enough boxing fans interested in watching it on the TV anymore. IF Ricky and Khan both went to Ch5 and made a point of the mass audiences interest then maybe but that hope has now diminished.